package com.ruoyi.system.utils;

import java.security.SecureRandom;
import java.util.*;

/**
 * 序号生产工具类
 * @author lsh
 *
 */
public class NoCreateUtil {

    private static final Random RANDOM = new SecureRandom();
    private static final String SYMBOLS = "0123456789";

	/*
	 *根据类型actionType 生成15位的码值
	 *actionType 必须位4位大写字母开头 
	 */
	public static String gen15NumberWithType(String actionType) {
        StringBuilder result = new StringBuilder();
        Set<String> set = new HashSet<String>();
        Double random = Math.random();
        String str = random.toString().substring(2, 9);
        set.add(str);       
        Date current = new Date();
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("MMdd");
        String time = sdf.format(current);
		return result.append(actionType).append(time).append(str).toString();      
    }


    /**
     * 获取长度为 6 的随机数字
     * @return 随机数字
     * @date 修改日志：由 space 创建于 2018-8-2 下午2:43:51
     */
    public static String getNonce_str() {

        // 如果需要4位，那 new char[4] 即可，其他位数同理可得
        char[] nonceChars = new char[6];

        for (int index = 0; index < nonceChars.length; ++index) {
            nonceChars[index] = SYMBOLS.charAt(RANDOM.nextInt(SYMBOLS.length()));
        }

        return new String(nonceChars);
    }



    /**
     * 生成邀请码
     */
    public static String genRandomNum(){
        int  maxNum = 36;
        int i;
        int count = 0;
        char[] str = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k',
                'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
                'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
        StringBuffer pwd = new StringBuffer("");
        Random r = new Random();
        while(count < 8){
            i = Math.abs(r.nextInt(maxNum));
            if (i >= 0 && i < str.length) {
                pwd.append(str[i]);
                count ++;
            }
        }
        return pwd.toString();
    }
    public static String generateUniqueUUID() {
        Set<String> usedUUIDs = new HashSet<>();
        String uuid;

        do {
            uuid = UUID.randomUUID().toString();
        } while (usedUUIDs.contains(uuid));

        usedUUIDs.add(uuid);
        return uuid;
    }

    public static String getID(){
        return (genRandomNum());
    }
    public static void main(String args[]){

        System.out.println(NoCreateUtil.getID() + getNonce_str());
    }

}
